[Electro-olfactogram after unilateral section of the olfactory nerve in the frog]

Changes in the amplitude of electroolfactogramm (EOG) after unilateral section of the olfactory nerve has been investigated in Rana temporaria. The EOG decreased during the first postoperative fortnight, but there was not a single case of complete disappearance of EOG at all recording sites on the epithelial surface. The EOG amplitude began increasing gradually towards the end of the third week and was about 80-100% of the control value in the middle of the tenth week. The amplitude of the EOG recorded in the contralateral olfactory organ decreased too, but its decrease was less pronounced and the complete recovery of the EOG amplitude occurred earlier. The character of changes and maximum decrease of the EOG amplitude after axotomy varied in different parts of the olfactory organ. In the caudo-lateral region of the organ the EOG amplitude decreased earlier and its recovery here began later than in the centro-medial one.